Denali’s official elevation figure of 20,310 feet (6,190 metres), established by the United States Geological Survey in September 2015, was the product of a thorough remeasurement of the mountain’s height conducted earlier that year using state-of-the-art equipment. The new value superseded the long-standing figure of 20,320 feet (6,194 metres) that had been the official elevation since the early 1950s. Earlier attempts to measure the mountain’s height had yielded different values. One such survey, conducted in 2010 using advanced radar technology, was made public in September 2013 and gave its elevation as 20,237 feet (6,168 metres). However, that measurement was subsequently determined to be inaccurate.

Denali lies about 130 miles (210 km) north-northwest of Anchorage and some 170 miles (275 km) southwest of Fairbanks in Denali National Park and Preserve. The mountain is essentially a giant block of granite that was lifted above Earth’s crust during a period of tectonic activity that began about 60 million years ago. It rises abruptly some 18,000 feet (5,500 metres) from Denali Fault at its base to the higher, more southerly of its two summits. The upper half of the mountain is covered with permanent snowfields that feed many glaciers, some surpassing 30 miles (48 km) in length.

In 1794 the English navigator George Vancouver sighted the mountain from Cook Inlet (an arm of the Gulf of Alaska). The first attempt to climb it was made in 1903 by an American judge, James Wickersham, but it was unsuccessful. A much-publicized but fraudulent claim by the physician and explorer Frederick A. Cook that he had reached the top inspired the conquest of the North Peak in 1910, by two prospectors of what was dubbed the “Sourdough Expedition.” On June 7, 1913, Hudson Stuck and Harry Karstens led a party to the South Peak, the true summit. A climbing party was first airlifted onto the mountain’s flanks in 1932; beginning in the 1950s, that became the standard way to attempt a summit climb, as it reduced the trip by several weeks. Most climbers are now flown to a base camp on southern-facing Kahiltna Glacier at an elevation of 7,200 feet (2,195 metres), where the greatest number follow the West Buttress route. On average, several hundred climbers attempt to reach the summit each year.

The mountain was known to the Athabaskan Indians as Denali (“The High One” or “The Great One”) and to the Russians as Bolshaya Gora (“Great Mountain”). It was called Densmore’s Mountain in 1889 by Frank Densmore, a prospector. The name Mount McKinley was applied in 1896 by William A. Dickey, another prospector, in honour of William McKinley (who was elected president of the United States later that year) and became the official name. Efforts began in the mid-1970s to restore the mountain’s original Native American name but faced opposition, mainly from lawmakers from Ohio, McKinley’s home state. However, the mountain’s original name was recognized by the state of Alaska, and it was adopted as the name of the national park and preserve when it was created in 1980. Use of the name Denali for the mountain became increasingly common, and in 2015 it was officially renamed Denali.